I have a set of Begali Adventure Paddles. They are wonderful paddles. I have the mount for my IC-705, KX2, and desktop. Each mount works well. However, there are times when I do not have a stable platform for my radios or the paddles. At these times I usually hold the paddles in my hands. My go to handheld paddles are my N0SA SOTA paddles. I got mine from his last run. They are an excellent paddle.
I tried holding the Adventure paddles in my hand but I would cause errant dits and dahs. I first thought I would 3D print a box for the paddles--to much thought. I then thought about getting some square aluminum tubing. Too expensive. I scrouged around in my shop and found some 1" angle aluminum. Perfect. Before I go on let me explain, that this was done with hand tools. A hacksaw, files, hand drill and drill bits. I also used a Dremel tool a little. This project is far from perfect. I never let perfection be the enemy of good enough.
Here is the piece roughed out.
The slot is where the finger guard mounts to the bottom of the paddler using a 4-40 screw. Mounted it looks something like this.
The guard extends past the end of the paddles to help protect the cable where it enters the paddle.
In use the paddle/guard combo looks like this.The guard keeps my index finger from touching the paddle lever and allows me to put my thumb below the paddle lever on the other side. It is very comfortable to use even with my large mitts.
A coat of primer, followed by paint and a clear coat and viola!, it is finished.
I will let it cure overnight and it will be ready for the next adventure. 73-de Scott
In one of the forums I visit there were a lot of questions about what radios and antennas to get for a new Amateur Radio Operator. I have bought/sold/traded many radios over my 29 years as a amateur radio operator and feel I have a pretty firm grip on what a basic setup would look like. I am not going to do a good/better/best list as I feel a good list will leave an operator wanting something better and a best list is usually cost prohibitive and can be technically advanced for most beginners. Better is "the just right". This range is usually only a little more expensive then the good range and the equipment is still easy to use and has more than enough performance.
Primarily for this post, I will be concerned with Emergency Communications (EmComm). More specifically net operations using digital modes. The equipment list will be geared for either home or portable operation.
Radio. Whatever radio you choose make sure it is capable or 100 watts output and does not require a separate sound card. A sound card whether built into the radio or external is required for most digital modes used today. You want a 100 watt radio for 2 reasons: 1) The purpose is this setup is for EmComm. It may be critical for you to make the communications link with the net control station. Being able to run 100 watts even if for a short period of time is better than maxing out at 5 watts and not making the connection. 2) Digital modes have a high duty cycle. Running a 5 watt radio at 5 watts because they often have a very small heat sink, heat very quickly. A 100 watt radio can run at 40 watts all day long and not even get warm.
My choices. The radio I recommend for new hams is the Icom IC-7300 at HRO. It is easy to use and setup, has a built in sound card, and the best metering for digital modes.
With the IC-7300 you can view all of the meters at once. Runners up are the IC-7100 at HRO and the Yaesu FT-710 at HRO . I find that the FT-710 and IC-7300 (I have owned/own both) hear about the same. I prefer the ergonomics of the Icoms better. With the radio I recommend Portable Zero RailsPortable Zero Rails to protect the radio and make it easier to handle.
Antenna Tuner/Match. I recommend an external antenna tuner/match. Most built-in tuners will match the impedance of an antenna up to 3:1, and external antenna tuner such as an LDG Z-11 Pro II or LDG Z-100A which will match up to 10:1. This is important if you are using a non-resonant antenna or one that is electrically short or long.
Antenna - Home. I have used many antennas over the years and I have developed my go to antenna list. For the home station, I have settled on either an 80 meter half wave dipole (~132 ft) or 160 meter Off Center Fed (OCF) Dipole (270 Ft). I have a slight preference for the OCF and they can be had in 80 meter versions. The 80 meter dipole can be homebrewed and the OCF dipoles can be found hereBuckmaster Antennas. It is important to note that most EmComm operations happen on the 40 meter and 80 meter bands. An 80 meter antenna will work reasonably well on 40, 20, and 10 meter bands but a 40 meter antenna will not work well on 80 meter. Bigger is better.
Antenna - Portable. I have used a lot of portable antennas over the years. I have narrowed it down to 3 favorites. The antenna I probably use the most is a 28.5 Ft random wire antenna with a 17 Ft counterpoise. It is easy to set up and works well 80-6 meters. If you look at my activations on this blog I have QSO Maps to show real performance. I will include a link on how to build the 28.5' Random wire antenna. My second favorite is a Chameleon EmComm II Ver. 1 Chameleon EmComm !! ver.2. I usually set it up as a ~60 Ft antenna in an inverted L configuration with a 55 Ft counterpoise. This antenna performs very well on the lower bands to include 160 meters. The last antenna is somewhat of a specialty. I use it for SOTA or lightweight QRP operations. It is a 40 Meter OCF dipole that weighs a few ounces Chameleon OCF 40. I hang it about 10-12 Ft in the tree and sit below it using CW. Another antenna worth mentioning is my Frankentennawhich is a multi configurable antenna and I will post a link to it. along with the antenna is Coax cable. Dual purpose field/home coax, RG-8X will work just fine. For home only then you can move up to RG-213 or LMR400.
Grounding. For the home, it is a very good idea to ground your equipment. There are lots of good sources on how to do that. I run a ground rod in the ground and ground my equipment to it. When I am not using my station, I disconnect my radios from mains power, my computer, and the antenna. I also have lighting arrestors on my coax.
Power Home. I use an Astron 30 amp switching power supply for my radios. I have also used a Samlex Power Supplywith good results. In the field, if I have mains power or an inverter generator avaliable I use a Powerwerx 30 amp Power Supply. What I like about the Powerverx is it uses Anderson Power Poles for the connections. I put Anderson Power Poles on everything. The main advantage is they prevent cross wiring and the destruction of your radio. If mains power is not available, I have batteries and solar panels to power my radios and laptop. A note about generators. Be very careful about what generators you hook your radios up to. Home Depot or Lowes generators (the cheap ones) are not well regulated and can damage your equipment. If your have to use one of those, run your radio through a deep cycle marine battery and use the generator to charge the battery.
Computers and software. Running amateur radio apps does not require a lot of horsepower or memory. Most Intel I-3 or I-5 processors will do fine. Celerons will work though I am not fond of them. For operating systems your choices are usually Windows or Linux. I run Windows 11 on my machines. For apps, you should have FLDigi, FLamp and FLmsg. For versatility, I use laptops. Keep your operating systems and apps up to date, don't muck with the machine too much, and you should be fine.
Go boxes. There's a lot of info out there about building Go Boxes or setting up your radios in a rack mount case. It's fine until you have to work with it in a limited space - been there, done that. What I use is a Dewalt Tough System tool box that holds just about everything I need except for a laptop. Here is what it looks like.
This should be enought to get you started or at least thinking about your next steps.
Before I take my leave from EmComm and revert to FunComm, I thought I would share some of my meditations on digital modes.
My use of digital modes goes back to the mid-2,000’s. I was an early adopter of Winlink and ran a regional digital PSK31 net. I have had the pleasure of working with many fine amateur radio operators with many different skill sets. Recently, I have had the opportunity to run a national digital PSK31 net for a few months. Again, the experience of working with amateur radio operators was a fun and fulfilling endeavor. I have used most of the modes for Winlink with VARA being the current favorite. Other modes I have used include PSK31, PSK125, QPSK125, Contestia, MT63, and Olivia. They all work as intended, however, when it comes to the less experienced digital operators, PSK31 is the easiest to master. I have run nets where we started on PSK31 and then moved to another mode and then back to PSK31. Many ops do fine on PSK31; however, once we move to a different mode, they get lost. When considering EmComm we should always play to the least common denominator.
My favorite modes for EmComm are:
1) Winkink/Vara. If I had to choose one, this would be it. With nodes all over the world, the probability of getting into a node is greater than if you had to depend on a single point. Because messages are stored until they are retrieved, Radios do not have to be left on to forward and retrieve messages. This can be done at any time and there is no need for a schedule. An operator can wait until favorable propagation exists. I have not tried VARAC yet, but it is on my to-do list.
2) PSK 31 and 125. I like PSK31. I have run a national net using it. Typically, I take check-ins on 31, send a message using FLMsg on 125, and then go back to 31. I have a much higher percentage of people getting the message using PSK31 than with other modes. On most modern radios, PSK31 can be decoded and sent without the use of a computer. While those at home with mains power see that as frivolous, a computer or laptop can be a serious drain on a battery when mains power is not available when operating under potable/emergency conditions. Because PSK31 has a narrow bandwidth (60 Hz) compared to MT63-1000s (1000 HZ), it enjoys a 2 S-unit advantage. Roughly that means a PSK31 message transmitting at 5 watts is equivalent to an MT63-1000s message transmitting at 100 watts (5 watts to 100 is about 2.2 S-unit gain and PKS 31 to MT63-100 is about 2.03). My point of view here is someone operating in the field, using portable equipment. In addition, we do not always get to choose who is in the field and who is at home. Throughput on PSK31 is about 50 wpm and MT63-1000 is about 100 wpm. If we bump up to PSK125 (which is about 1 S-unit better than MT63-1000) we get about 200 wpm.
3) My third mode would be CW and this would be used when nothing else is working. It requires the least amount of equipment and what can be used is not complicated. This would be an emergency mode. Any communications plan should include CW and any EmComm group should try to maintain a few CW ops on their rosters.
What would I do if I was in charge? I would try to keep the communications plan as simple as possible and play to the least common denominator. I would use the U.S. Army acronym PACE which stands for Primary, Alternate, Contingency, and Emergency. My plan would look something like:
a) Primary – normal infrastructure/internet-based communication. When it’s working, it’s the best. I have seen operators try to use their radios when there is a working FAX machine next to them.
b) Alternate – This could be a combination of Voice/SSB and Winlink. Establish a voice net because that is where most of the operators operate and provide an email address where to send Winlink Messages.
c) Contingency – This could be a Peer-to-Peer digital mode such as MT63-1000, or VARAC. I like the idea of VARAC because VARA is used by Winlink but I have to try it out before I can recommend it. Down at this level, the more experienced ops may not be prevalent, and it might be the less informed ops on the scene.
d) Emergency – This is no man's land in the EmComm community. The probability of us getting to Emergency is quite low, maybe 1%. Here you might find an operator with a radio and antenna while a geomagnetic storm is raging overhead. I have been deployed to a disaster area while a storm was raging, and we have had a couple of SETs with poor band conditions. Here might be the realm of PSK31 and/or CW.
What I am saying is to keep your comm plan simple. You don’t have a legion of professional-level operators on hand that can tackle all the modes available. What you do have are operators with widely varied skill levels, with amateur radio either a secondary or tertiary interest. Pick the fewest modes that use the fewest different types of software and stick with them. Don’t forget to train, train, train. Additionally, have exercises that get operators out in the field. Field ops are hugely different than operating from home. Try to get them at least 20 miles from their home, this reduces the run home for something I forgot. Many times, during a deployment/exercise there were ops who could not complete the tasking. I like to go camping at least once a month and bring my radios with me. I usually do a POTA activation; it gives my radio system a good shakedown and helps me understand its performance. Get out, get on, and go do! 73 de Scott
This past weekend I camped at Ft Mountain State Park in northwestern Georgia. One of my goals was to test NVIS and see if it would work during my stay. I collected data using FT8 from Friday afternoon when I got set up until about 2130 hrs eastern when the 40-meter band started to fade.
Conditions. I set up in the campground in Ft Mountain State Park. My elevation was approx. 2,400 feet above sea level located in a depression (-200 Ft.). The antenna was a Chameleon EmComm II ver.1 in an inverted vee configuration. The ends were 6-6.5 feet off of the ground and the apex was 10-12 feet. There was a counterpoise run beneath the antenna. The radio was an Elecraft K3(s) running FT8 at 25-35 watts.
During my stay I made 121 contacts on 40 meters. 7-8 MHz is considered the upper limit for NVIS operation. NVIS is also not guaranteed as it relies on proper atmospheric conditions to reflect the radio waves back downward. When creating the following maps, I only included states where I had 3 or more contacts. In addition, some states had no contacts and that may have been due to propagation, or no one was on at the time. Also, I reported the average signal strength for the state (not individual stations) as well as the percentage of the contacts from that state based upon 121 contacts. If you add up all of the percentages on the following maps, they will not equal 100%.
The first map shows all of the states with 3 or more contacts.
Generally, a good signal for FT8 is any signal above -10dB. A closer view shows that except for Texas the stronger signals are within 300-400 miles of the transmitting station. The circle in the map below has a radius of about 350 miles. As you can see there is a rather sharp drop off in signal strength beyond about 350 miles.
While this isn't a proper detailed experiment, some generalizations can be made. The transmitting station was located in a depression (-200 Ft), there is a good probability that NVIS was used. The signals close in were stronger, meaning that the signals were within the skip zone and that signal strength beyond the skip zone (beyond about 350 miles) noticeably dropped off indicating NVIS operation. There were more stations contacted within the circle. As the transmitting station turned away from the sun the ability to copy close in stations diminished. The white elephant in the room is Texas. In my experience, there always seems to be a radio pathway between Texas and Georgia. Not sure why that is but in all my activations and at home there always seems to be at least one Texas station in the mix.
As amateur radio operators, we often think in terms of how far we can reach, how many miles per watt, to reach that atoll on the other side of the world. What is equally important and in some cases such as EmComm, is how close can we get. Sometimes the most important link is just on the other side of the mountain. Knowing how to utilize NVIS in your comms plans will help bridge that gap. You may be saving a life instead of collecting a QSL card.
My first experience with Near Vertical Incidence Skywave (NVIS) propagation was during Hurricane Frances, in September 2004. We were bringing two tractor-trailers full of food and supplies to an area on the east coast of Florida. I was the EmComm Specialist, and my function was to ensure that adequate communications were available. I was new to this, and this was my second deployment. I recently purchased an Icom AH-4 to go with my IC-706 MKIIG. I was looking for something that could quickly be deployed and recovered while providing a reliable linkage. I also had some Hamsticks with me. The antenna was about 30’ of 12ga THHN wire and the counterpoise was about the same length of bare flat-braided wire. Before we reached our destination, we stopped in Jacksonville, FL to allow the hurricane to pass before we proceeded south. That evening, I deployed the antenna to test it. This was a hurried callout and I had little warning.
That evening, I called to check into our 75-meter EmComm net. I was amazed that I sent and received a 59-signal report from an antenna that was only about 6 feet off the ground. The distance between the two stations was about 300 miles! Back then, I didn’t know about NVIS, but I proved the concept. It works and it works well.
Today, there is a renewed interest in NVIS with Georgia ARES and Georgia AuxComm. I wanted to present a Cliff Notes version of NVIS to help others get a leg up on this form of propagation. Throughout this series, my two main references will be Near Vertical Incidence Skywave Communication, Theory, Techniques and Validation by LTC David Fieldler and Maj Edward Farmer, and FM-24-18 Tactical Single-channel Radio Communications Techniques. When I use a reference, I will abbreviate the (NVIS) or (FM24-18). Italicized text is a direct quote. What is NVIS? NVIS is skywave propagation where radio energy is radiated at or near vertical at a low enough frequency to be reflected by the ionosphere back toward the earth. This causes an omnidirectional pattern like a fireman’s fog nozzle pointed up (FM24-18). This pattern eliminates the skip zone allowing communications within a couple of hundred miles and because the path is near vertical terrain such as mountains can be overcome.
Typical propagation with Skip Zone
NVIS Footprint or Fog Nozzle pattern
What is needed? NVIS needs frequencies low enough to prevent them from penetrating the ionosphere (F1/F2). This usually means frequencies in the 2 to 4 MHZ region at night and 4 to 8 MHz during the day. This would include the 160-, 80-, 60-, and 40-meter bands (NVIS). Note: It is important that tactical and emergency communicators develop strategies for implementing medium frequency (160-meter) NVIS paths (NVIS). There will be more about this in the discussion about propagation. Also needed are antennas that radiate at 75 to 80 degrees or greater from horizontal and that suppress groundwave radiation. NVIS depends on skywave radiation. Because of the time differences between skywave and groundwave radiation reaching the receiving station, there will be some cancelation in the form of fading (QSB) which may be enough to reduce effective communication. I will have more information about antennas in an upcoming discussion. NVIS isn’t mystical, magic, or arcane – well maybe a little arcane until now. What successful NVIS operations need is a little effort from the participants. There must be some skill with equipment, along with some knowledge about theory such as antenna design and propagation. What it really needs is careful planning and an adequate communications plan along with practice. I have a couple of installments planned that should give the average ham enough specialized knowledge to be able to conduct successful NVIS operations. My one caveat for this section is that there will be times when NVIS will not work. Your communication plan should accommodate that.
One of the critical skills needed for successful NVIS operation is determining which frequency or band to use when or if NVIS propagation is even possible. Luckily, today there are online propagation prediction tools to help us. In order to use these tools we need to understand a few terms. Most of us know or have heard of the MUF and LUF, which stand for Maximum Usable Frequency and Lowest Usable Frequency. What a lot of us don’t understand is the MUF and the LUF frequencies tell us that the path will be open at the LUF or the MUF only 50% of the time (NVIS). What we need is the FOT or the Frequency of Optimum Traffic. This gives us a path reliability of 90%. It will frequently be about 50 to 85% of the MUF (NVIS).
To find the FOT, use a service like https://www.voacap.com/hf/ and input the transmitting and receiving stations. Then look for Best Frequency at the bottom of the map to find the FOT and viola! That and all sorts of other info are available. A couple of things to remember. NVIS typically happens below 8 MHz. If the FOT is above that, then NVIS propagation may not be possible. This website provides a lot of information and not all of it may be applicable to NVIS. Software like VOACAP is designed for long-path propagation for broadcast stations.
When preparing a communications plan whether for a weekly net or emergency communications, a propagation study should be completed. This will help determine which bands are best and when. Today 11/22/23 at 1845 hrs UTC, the FOT is 27 MHZ.
I have poured over a lot of documentation about antennas. Through it all I have come up with the following antennas for portable/field use. The best antenna is a horizontal half-wave dipole at 0.1 to 0.24 wavelengths above electrical ground. As long as the height stays below 0.25 wavelengths, its efficiency isn’t affected that much. Much of what I read has a height somewhere between 15-30 feet. There are even a few who advocate putting the antenna within inches of the ground. The antenna can be allowed to sag in the center for a little gain or it can be hung in an inverted vee as long as the apex angle is 120-140 degrees.
What about the AN/AS-2259? Good question. I built one back in 2007 and used it a few times. It can be a pain to set up and I am not sure the juice is worth the squeeze. Concerning the AS-2259 vs a half wave dipole: In most cases, a standard dipole is as easy to install and performs significantly better (NVIS).
Height above ground. There are two components to antenna height – the part you see and the part you don’t see. The part you see is represented by the length of the mast holding the wire above the earth. The part you don’t see is the portion below the apparent surface through which the radio waves travel before reflecting. For very conductive ground, such as seawater, radio waves reflect on the surface. For poor ground, such as freshwater, radio waves penetrate many feet. An antenna lying on the surface of rocky soil, for example, might have an effective “height” of 40 feet or more. (NVIS) The second antenna is a military whip either 16’ or 32’ attached to a vehicle and used with a coupler. The whip is tilted horizontally away from the vehicle and the vehicle serves as a ground. This creates an asymmetrical dipole. These whips are hard to get and are often expensive. The whip can be replaced with a wire and the length can be extended to 60-100 feet or more and/or a counterpoise can be used. This is a similar setup I used in Jacksonville, FL back in 2004. Another variation of this antenna is Chameleon’s EmComm series. All the antennas mentioned work.
Remember an antenna NVIS should enhance near-vertical radiation and suppress ground wave radiation. Antenna 0.25 to 0.1 or less wavelengths above the ground should provide adequate or better NVIS performance. Any adventure into NVIS starts with a communications plan and propagation study. As I said at the beginning of this series, this is a Cliff Notes Version, enough to get you interested and going. One thing that must be remembered is that NVIS doesn’t always work, and the communications plan should include a contingency for using long path or other forms of communication such as WinLink.
I like to use random wire antennas. My favorite is a 29.5' antenna with a 17' counterpoise. I usually use a 5:1 (Chameleon) or a 9:1 (homemade UnUn with it. I have noticed with either combination, some stray RF finds its way back to the radio and me. To combat this, I have a Chameleon Choke balun which is nice but it is rather clunky and uses RG-8X coax. There are times when I am operating QRP, I use RG-316. So I decided to see if I could make a Choke balun using RG-316.
For a toroid, I found a FT114-31 from KF7P Metalwerks. These are rather small.
The toroid I believe cost about 3 bucks plus shipping. I had a 3' RG-316 jumper with BNC connectors on each end. With a little bit of fiddling, I got 6 turns through the toroid without having to cut a connector. The next step was to straighten out the turns and set them in hot glue. I also applied a ty-wrap at turns 1 and 6.
Hot glue is never an easy medium; this time I managed to keep it off of me. Even though it is messy looking the turns are secure. Toroids are generally brittle and can easily break. I am not always gentle with my gear so I decided to first wrap the toroid in coax seal or "elephant snot". This will seal out the weather and provide a little bit of a cushion. After putting it on I molded it to the toroid.
Because this stuff is very sticky, I then wrapped it in Scotch 88 electrical tape.
The whole thing weighs in at 3 ounces and should handle somewhere up to 70 watts. It ain't pretty, but I have less than 10 bucks rolled into it. I will be taking it out this weekend to a park to try it out. I to hear you out there. 73's Scott
UPDATE 08/16/2022
Today I managed to get into town and buy some wire for my choke project. While there, I bought some heat shrink tubing for my first project. The heat shrink cost more than the little box I had for my second choke. Here is the revised choke with the new heat shrink along with the new choke.
The new choke is made with 16 ga wire, I could've and probably should've used 18 ga. The toroid is a FT114-31 and it is wrapped 6 turns. the toroid is secured to the bottom of the box with hot glue. Here is a picture before I put the lid on.
Here is the final product.
The box weighs about half an once more than the coax choke. Of the two, I prefer the box, mainly because the toroid is wrapped with primary wire and not coax. It's a little easier to wrap and looks neater. More than likely, both will perform about the same. For my next outing, I will have an antenna totally made by me. 73 de Scott
There is always a lot of talk about QRP vs QRO, 5 watts vs 10, ad nauseam. So today I thought I would run the numbers and see what the real deal is. First we need a few definitions. An S-unit in general terms is the minimum change in signal strength to be just noticeable (k3wwp.com). In more technical terms it equates to approximately 6 db in change. The decibel (dB) is a logarithmic number. Each 10 dB represents a factor of 10 difference. This may be a little out there for some so we will cut right to the shortcut. There are two types of logarithms. For calculating dB, use the common logarithm which is base 10. To see if your calculator uses the right one. Punch in 100 and then log. The answer should be 2 which equates to 10 to the second power which equals 100. This is not a technical paper but an entry way to see how changing the power levels affect the signal level of your transmitting signal. As you guessed, it is not linear.
Let me introduce an equation:
Where Power P1 is the power you wish to evaluate and reference power P2 is your starting power. Let's take going from 5 watts to 10 watts. The equation would look like this:
We take 10 and divide it by 5 which give us 2. Then we hit the log function on our calculator which gives us 0.301. Multiply that by 10 and you have about 3 dB in gain or about one half of an S-unit (remember 1 S-unit is equal to 6 dB). Let's do one more by hand and tackle the QRP/QRO debate. How many S-units will increasing power from 5 watts to 100 watts give you? The equation looks like this:
Take the 100 and divide by 5 to give you 20 and then hit the log function to give you 1.301. Multiply by 10 for 13.01 dB. Divide 13.01 by 6 dB and you have 2.17 S-units. Going back to our definition that one S-unit is the minimum change in signal strength to be just noticeable shows that going from 5 watts to 100 watts is not that great of a change.
Let's let the other shoe drop. What about going from 5 watts to 1500 watt? That will give you 4.13 S-units of gain vs 1.96 S-units going from 100 watts to 1500 watts?
This gives you a fairly easy equation to help you evaluate your needs based upon empirical data. Running 20 watts over 5 gives you 1 S-Unit. Using less power means less drain on the battery for longer operation. This is only part of the equation. Propagation, antenna, mode used, and station efficiency all play a part. Have fun and maybe don't toss the QRP radio yet :)
Today's dalliance is UnUns. An UnUn which stands for Unbalanced to Unbalanced is a transformer of sorts which in this case matches or attempts to match the impedance between an antenna and a transceiver. Today I am making a 9:1 ratio UnUn which is suppose to match a 450 ohm antenna to a 50 ohm transceiver. When the impedance is matched between a transceiver and an antenna, maximum power from the transceiver can be transmitted to the antenna. A 9:1 UnUn is used with random wires and a counterpoise. I call this UnUn QRO because it is rated at 250 watts. I would use this in the field with a radio like my IC-7300 even though I rarely go above 50 watts. I went QRO because this is my first turn at winding a toroid and I thought starting with something larger would be easier.
I will only list project specific parts. The toroid kit come from Palomar Engineers https://tinyurl.com/3tkctj2e. This gives you the toroid, wires and instructions. The other project specific part is the case which came from amazon https://tinyurl.com/2p93h9r5 Everything else is generic parts that I either had on hand, purchased locally or from amazon.
The Palomar Kit looks like this.
The kit comes with decent instructions but, with a couple of caveats. One, the wire that comes with the kit appears to be random. The colors of the wires, do not match the colors in the instructions. this is not insurmountable, just makes things a little more difficult especially for first timers like me. The second nit is the pictures provided, while of decent quality, are black and white. In today's world, color photos should not be that big of deal. The kit can be wired as a BalUn or UnUn. The way I overcame the mentioned shortcomings was to annotate the schematic they provided.
The UnUn is the schematic on the right. According to the instructions, the 3 wires are wound 10 times or turns with each pass of the wires through the center of the toroid counting as one turn. The wound toroid looks like this.
Before I went any further, I tested the toroid. I did this by hooking up a 450 ohm 50 watt resister to the antenna and counterpoise leads and attached my Xiegu X6100 to the input of the UnUn. I then used the SWR Sweep function on the X6100. I knew this wouldn't be an exact science since I was using a 12" RG-316 cable and 12" jumpers, but should be close enough to see if I am in the ball park. Here are a couple of the test.
Shown are 160 meters, 30 meters, and 20 meters with all showing an SWR of ~3:1 or less. Not too shabby. With a random antenna wire of around 49 feet and a 25 foot counterpoise, I expect the SWR to even be less. That means anything from 160- 20 are well within the capability of most tuners. I suspect that I may be able to get down to 10 meters once I hook it up to a real antenna.
The case was a guess on my part, but as it turns out, it was the right size.
Then all put together, it looks like this. The toroid is mounted on a sheet of plastic and glued into the case.
The input connector is BNC and the screws are 10-32. I have some 10-32 wingnuts on the way to make it easier to attach wires. The eyebolt was to help take some of the strain off of the antenna wire and BNC connector is on the bottom to help protect it from the weather. One final test.
This was a fun little project and gave me some experience and confidence making UnUns. My next project will be a QRP UnUn. I mostly operate QRP when out in the field (max 10 watts. I know). However, some of the stuff I bring is QRO rated. I am trying to reduce the load. Making antenna parts that are QRP rated instead of QRO rated, reduces weight and space. Right now I am doing POTA activations, but hopefully this fall when the ticks and chiggers die off, I will try my hand at SOTA. 72 de Scott
